The invention relates to an antenna apparatus, system and method for providing signals received from a satellite broadcast system to a radio receiver. More particularly, the invention relates to an antenna coupled to a transmission line integrated with a window clip mounted on a vehicle window, the interior portion of the transmission line being connectable to a radio receiver.
A number of methods exist for transferring radio frequency (RF) signals through a window in an automobile. For example, an antenna can be attached to a window using an adhesive, and RF signals can be transferred to an apparatus on the inside of the window using capacitive coupling, slot coupling or aperture coupling. Typically, as is known in the art, the antenna system consists of a transmission line, a coupling device such as a capacitive plate, a slot, or an aperture, a matching circuit between the transmission line and the coupling device, and the antenna itself.
Known coupling methods require matching to the transmission line, that is, the RF signals transferred through the glass must be adapted to the particular transmission line, adding cost to the apparatus. Additionally, there is inherent signal loss due to coupling of approximately 1 dB or more, as well as an insertion loss due to the matching circuit.
Examples of prior vehicle antennas are disclosed in the U.S. Pat. No. 5,898,408 to Du, U.S. Pat. No. 4,882,592 to Studer, Jr. et al., U.S. Pat. No. 5,099,251 to Fisher, U.S. Pat. No. 4,799,098 to Blaese, U.S. Pat. No. 4,266,227 to Blaese, U.S. Pat. No. 4,109,251 to MacDougall, U.S. Pat. No. 5,850,199 to Wan et al., and U.S. Pat. No. 5,898,407 to Paulus et al.
Thus, there is a continuing need to provide an improved antenna system that reduces or eliminates signal loss caused by coupling.
In accordance with the present invention, an antenna system is provided for the reception of radio signals and transmission of the radio signals to a radio receiver where the radio signal is transmitted over a transmission line carried by a clip where an outside end of the transmission line is electrically connectable to an externally mounted antenna and an interior end of the transmission line is connectable to a radio receiver.
In accordance with one aspect of the present invention, a U-shaped clip is provided that is removably attached to an edge surface. The clip has an open end and a closed end, the open end being configured to receive the edge surface. The clip comprises a first member, a second member and a third member, the first member and the third member being disposed on opposite sides of the edge surface. The closed end is configured from the second member extending between the first member and the third member. A transmission line adapted to transport signals from the antenna is carried by the clip. The transmission line extends between the first member and the third member along the second member, wherein at least one of the first member, the second member and the third member are planar and comprise a first layer and a second layer between which the transmission line is disposed so as to enclose at least a portion of the transmission line between the first layer and the second layer. The first layer separates the transmission line from the edge surface. The second layer prevents exposure of the portion of the transmission line.
In accordance with another aspect of the invention, a clip is adapted for removably attaching to an edge surface of a vehicle. The clip is a U-shaped member comprising a first member, a second member and a third member. The first member and the third member are disposed substantially opposite each other on the interior and exterior, respectively, of the vehicle when the clip is attached to the edge surface. The second member extends between the first member and the third member and is disposed between the edge surface and at least one of the frame and the roof of the vehicle. A transmission line is adapted to transport signals from the antenna and be carried by the clip. The transmission line extends between the first member and the third member along the second member. At least the second member of the clip is planar and comprises a first layer and a second layer. The transmission line is disposed between the first layer and the second layer. The first layer separates the transmission line from the edge surface. The second layer separates the transmission line from the at least one of the frame and the roof of the vehicle.